Automatic telephone system



Aug. 10 1926.

F. A. LUNDQUIST AUTOMATIC TELEPHONE SYSTEM Original Filed July' 14, 1922 5 Sn ets-Sheet 1 M A u in] M1] I ll]! -Inusn 01: Frank film-11f m5 5%. Z.

Aug. 10 1926. 1,595,204

F. A. LUNDQUIST AUTOMAT IC TELEPHONE SYSTEM Original Filed Ju1y l4 1922 3 Sheets-Sheet 2 Aug. 10 1926. 1,595,204

F. A. LUNDQUIST AUTOMATIC TELEPHONE SYSTEM Original Filed July 14, 1922 :5 Sheets-Sheet s nuenlzj rank fi -LIIL'LCEITLT Patented Aug. 10, 1926.

UNITED STATES PATENT OFFICE.

FRANK A. LUNDQUIST, OF CHICAGO, ILLINOIS, ASSIGNOR TO HENRY S. CONRAD, OF KANSAS CITY, MISSOURI.

AUTOMATIC TELEPHONE SYSTEM.

Application fled July 14, 1922, Serial No. 574,987. Renewed December 16, 1925.

The present invention relates in general to automatic telephone systems, but is more particularly concerned with systems of this character in which pneumatically operated l switches are employed to complete connecp ions beween calling and called subscribers mes.

An object of the invention is to produce an air driven selector switch of simplified mechanical construction and having novel controlling circuits.

There are other objects of the invention, which. together with the above, will be described hereinafter, reference being had to the accompanying drawings forming part of this specification.

Referring now to the drawings comprising Figs. 13, inclusive, there is shown by means of the conventional circuit and mechanical diagrams a connection from the line of the substation A through the line switch C, the first selector E, the connector H, to the line of the substation A.

Referring now more particularly to Fig.

1, the substation A is of the usual automatic type, the line of which terminates at the exchange in the individual line or trunk selecting switch C.

The line switch C is a pneumatically operated switch which is very similar to the line switch disclosed in Fig. 1 of the drawings in Patent No. 1,495,755, issued May 27, 1924.

Reference is made to that application for a complete description of the mechanism. The line switch C has access to trunk lines, such as the one shown in the drawings comprising conductors 178, 195 and 192, which extend to first selector switches, the first selector E, in this instance.

The selector E, Fig. 2, is a pneumatically operated switch of the vertical and rotary type. The construction and circuits of the switch are so arranged that the sylphon which controls the vertical operation of the switch is normally in an operated position.

The selector E has access to trunk lines extending to connector switches, one of these trunk lines being shown in the drawings extending to'the connector switch H, Fig. 3.

The connector H is an air operated switch of the same type as that disclosed in Fig. 3 of the drawings in the-patent above cited to which reference is iilild for a com lete desicri tion.v

briefly. described the appal' t ls shown in the drawings, its detailed operation will now be explained. For this purpose it will be assumed that the subscriber at sub-' station A desires to extend a connection to the line of the substation A. In order to do this the calling subscriber will remove his receiver and operate his calling device in accordance with the digits of the called subscribers number.

When the receiver is removed a circuit is completed for the magnet 33 extending as follows: battery X, upper winding of relay 33-172173 174 171 substation A 170-175-175 175 lower winding of relay 33 to ground. This causes magnet 33 to attract its armature 34, to first open valve and to then close springs 180 and 181. Opening valve 35 admits air to motor 20 which immediately rises, carrying its wipers on a trunk hunting movement over the bank contacts shown above them, and permitting spring 301 to engage spring 302. When the wiper 179 reaches a contact which has a ground connection. as for example, the contact associated with conductor 178, a circuit is completed as follows: ground in the selector E, resting contact of spring 313 and said spring, through the winding'of coil 301, springs 370, conductor 17817918224 1S318()181186-184184185 to battery.

This operates magnet 24 to throw pawl 2 into the ratchet teeth 23 and to stop the upward movement of the motor 20 with its wipers on the terminal of the selected trunk. The attraction of the armature 25 by the magnet 24 also opens the valve 28 to admit compressed air to the sylphon 32. The operation of this sylphon shifts the adjacent contact springs to their alternate position and also moves the lever 200 to throw the pawl 27 onto the teeth 22 and to close springs 187 and 188. When the sylphon 32 shifted the adjacent contact springs it opened the circuit for the magnet 33 at 174 and 175, and at the same time caused these springs to operate springs for completing a circuit through to the line relay 300 of the selector. When the circuit is broken for magnet 33, the armature 34 falls back toopenthe cir cui-t for the magnet 24 but the lever 200 previo'usly closed springs 1-87 and 188 so that a locking circuit is maintained by the branch from 183 by way of .188*187*302184 1843- 202 ragweed. When the armature 34 falls back it permits valve 35 to close, with the result that air becomes exhausted in the motor 520. The pawl 27, however, holds the motor 20 againstfalling, and will continue to hold it as long as the sylphon 32 continues to receive air through valve 28.

The magnet 301 in the selector it was en ergized ovir the above traced circuit and by attracting its arn'isture 3l0 opened the valve 311 to permit air to be supplied to the sylphon 30?. The sylphon 30'? operates to allow the vertical and rotary pawls 318 and 319, respectively, to engage their associated ratchet wheels by operating the shaft 317. The operation of the sylphon 307 also causes the bell crank lever 312 to ope ate spring 31.3 thereby transferring the connection ot' conductor 178 from ground to battery. By the jockey pin arrangement or" the bell crank lever the spring 313 is locked in engagement with its working" contact. is the operation of the sylphon 32 in the line switch C shifts the connections of the magnet- Ql i'ron'i battery to ground the line switch C is main tained in operated position.

The operations above described result in connecting the line of the substation A to the line relay 300 of the selector over a circuit which extends as follows: Ground throu h the lett hand winding of relay 300. resting contact or spring 3?) and the said spring, conductor l95190l9l 13 1741Tlsubstation A 17 -1T5l89 190-192 spring 331 and its resting contact. and through the right hand oi? the line relay 300 to battery. Relay 300 es over this circuit and attracts its ture thereby closing valve whereby the air sup s disconnected from the sylphon 306. phou 306 immediately becomes inoperative thereby allowing the spring 335 to operate the pawl 33% to raise the switch sha'lt a partial step into such position as to be operated by the subsequent operations of the sylphon 306. The s},*li ilioi'1 303 also restores to normal after a short interval. However, A function at the present ime as the shaft of operated opposite the first level of bank contacts. The armature 371 on the line elay 300 is of the I iinn'iediately onerated when the relay is energized. The operation o't armature 3T1 closes a shunt path around the oil normal springs at springs 36'? so as to provide against opening the holding circuit which extends back to the line switch C when the oil normal springs are operated which occurs shortly after the operation of relay 300.. when the switch shaft is given its preliminar step.

The operations above described all take place automatically in response to the removal or" th receiver at substation A.

The subscriber at substation A is presumed to have an ordinary calling device local station, the operation of which as and then remakes the line circuit a 'red number of times. The rapidity "ii which the circuit is broken and remade is resumed to be too great to permit on 303 or the armature 371 to re response to the operation L vd break and remake of the hrough magnet 300 armature 35 i i c acted and tlien attracted. In falling l. gthe :u'n'iatiu'e opens the valve anc permits air to flow through the pipes 3-53 and 3% to the sylphon 306 and also to the slow sylphon 303. Upon belng attracted again, ztr is cut oil from the motors 306 r 1 A-S the armature 354C vibrates each and forth in response to the breaks and remakes of the circuit of the local station the motor 306 responds and moves with these pu sations but the motor 303 is made slow acting by the check valve 300 and mains in perated position. Each time the sylphon 306 dcenergizes it allows the spring to actuate the pawl 334: thereby raising 700 the switch shaft carrying the switch wipers inclusive, step by step until they are placed opp :ite the proper level of bank contacts as determined by the number of in terruptions in the digit dialled. Upon the first step of the switch shaft, the lever 35? is operated under influence ot the spring 322 and raises so that when the sylphon 303 be comes inoperative it will actuate the lever Shortly after the termination of the vertical movement of the switch the slow :tine sylphon 3023 becomes inoperative thercoy operating the lever This op eration closes the valve 3221 thereby permanently shutting off the supply of air to the pipe Sat-l so as to maintain the sylphon 306 deflated and also opens the valve 320 thereby allowing" air to be supplied to the sylphon 305. Syphon 305 moeratcs through the medium the pawl 31' to rotate the switch shaft carrying: the wipers in on the first set or banlr contacts. The operation of the lever 3 12 cau es the alve 330 to be closed thereby shutt oft the supply of air to the svlphon 305 which innnediately deflates and operates the valve 339 to again allo air to be supplied to the sylphon 305. In this manner the switch wipers are automatically l until engagement is made with a bro and 208, conductor 209, conductor 360, wiper 350, coil 302, spring 332 and its resting contact to'battery. Magnet 302 is energized overthe above circuit and attracts its armature 338 to stop the rotary trunk huntinot operation by permanentlyclosing valve A further result of the operation of magnet 302 is that at armature 350 the valve is opened thereby admitting 'air to the slow sylphon 304. The operation of the 'sylphon 304 disconnects the incomingtrunk conductors 195 and 192 from the windings of the line relay 300 andentends'them over wipers 351, 352 trunk conductors 361. 362. through the windings of the line relay 112-113, ot' the connector H. Bv the operation of spring 332. controlled by the-svlphon 304:.the test wiper 350 is'disconnected from battery and connected through a resistance to ground. The d'eene'rgiz'ation of the line rela'v 300 merely prepares certain releasing circuits as will subsequently appear.

In the'connector H the line relay 1l2113 is energized and operates its armature 115 to allow air to flow to the motor 118. Motor 118 is made slow acting by means of a check valve, as shown, and by the operation of spring 208 it connects the test connector 209 to battery wherebv a holding circuit is established for the coil 302 of the selector E.

The attraction of armature 114 of the line relay causes the valve 116 to close the other end of the pipe 231. of the line relav armatures. Armature 114 responds to impulses through the magnet 112113 while 115 is a slow armature which does not respond to such impulses 'but remains attracted until the break of the circuit through the magnet is of longer duration than occurs in the calling device.

The motor 118 also raises the lever 119 to engage the pin on disc 134 directly above its right hand end. and as the motor 118 continucs to rise. the disc 134 is rotated by the lever 119 far enough for the pin 137 to operate lever 140 to open the valve 142 and to permit compressed air to flow to the motor 127which-puts a horizontal strain on the carriage 124. In this operation the disk 134 is advanced so as to bring one of its teeth nearer to the pawl 150. It also permits pawl 146 to engage the disk 134.

The operations above described are automatic ones consequent tothe selector finding an idle connector. When the subscriber again operates his calling device. the consequent vibrations of armature 114 open and close valve 116 to permit pulsations of air to flow from pipe-231 through pipe 232 to slow motor 233 and to the escapement motor 121. The motor 233 opens valve 234 to permit air to flow to motor 147. and keeps air on motor 147 as longas successive impulses flow through magnet 112-113 The operation of motor 147 lifts rod 148 and brings subscriber to he called.

pawl 150. adjacent to the first tooth or notch in disk 134. It also shifts certain electrical connections to be described later.

The movement of disk 134. by motor 118 turned the rack 122 to engagement with the tail of the pawl 130 so that the pulsations going to motor 121 will operate said pawl to permit the carriage 124 to move under strain of motor 127' At the termination of the series of electrical impulses com .ing' as the result of the operation of the calling device, the armature 1.14 remains in at tracted position and the valve 116 closes. Closing valve 116 shuts air from motor 233 which in turn shuts air from motor 147 which falls back. This permits spring- 153 to force rod 148 downward. In this movement, the pawl 150 engages the disk 134 to rotate it one step, the effect of which is to turn the rack 122 from engagen'ient with the tail 132 of the pawl 130 into engagement with the lower end of a T-shaped lever as shown in Fig. 11 of my patent previously mentioned. The T-shaped lever is pivoted at its upper end at the intersection of the horizontal portion and the vertical portion of the T. On each end of the horizontal por tion of the T a pawl is pivoted for engageing in the teeth of a rack which is attached to the wiper carriage. By the movement of the T-shaped lever to its forward position one of the pawls is operated to engage and move the rack vertically a half step and on the movement of the T-shaped lever to normal position the other pawl engages and moves the rack another half step. this raising the wiper a full step for each complete operation of the T-shaped lever.

hen the subscriber operates his calling device to send a second series of impulses to this connector, motors 147 and 121 are operated as before. This time the reciprocations of the rack 122 move the carriage upward until the wipers carried thereby are on contact terminals which represent the At the termination of these impulses, the motor 147 and the rod 148 tall to advance the disk 134 another step which carries the rack 122 beyond and clear of the T-shaped' lever.

It will be assumed that the connector stops on the lower right hand bank contacts shown in Fig. 3 and that the wires leading from these contacts are the wires shown leading to the line switch of the called line, indicated by the reference character C. It will be understood thatthis line switch'is similar to the "line switch shown in 1 in all respects When engagement is made with this set of bank contacts the rod 148 is in elevated position but as soon as there is a pause in the impulses which move the connector to its desired position the motor 147 and the rod 148 fall back whereupon the circuit is completed as follows: battery F at the upper left hand part of Fig. 3. 2 1- :242private wiper 2 2 l5 normal wire to the switch shown. utter which v be traced follows rcterd to the line sw th circuit ma bein h so opens valve to admit a e on therebv shifting: the adacent contact springs. The complete ta ina' circuit is shown in heavv lines.

The signalling circuit has been omitted in order to avoid complications. and because ii: is no necessary to a full understanding the invention. It mav be any well known adaptation of ordinary devices to the presentarrangement.

Tl previous d tion assumed that the line switch of it? called s ation was in normal position. It. however. that line. switch had been mov d from its normal position by the subscriber calling then the ter minals of the normal wires would he opened and the connector would be unable to make connection with the called line.

It was assumed that the called station had not been connected with by some other If we assume that a connector .witch is in engagement with is banl; contacts associatea with the called line when the *ipcrs of the connector H re brought into er nement with the set of multiple contacts. the rod HS would be in its elevated position. Under these conditions a circuit will be c mpleted as "follows: "from battery on the test contact of a. called line where it been placed by the precediuglv operated connector. testwiper 2el l2 i2-260-coil 207 268-L 692T0 to around. The magnet is energized over this eirc and oper-te its armature 272 to move the bell crank 24 awav from the rod 148 so that when t e sai-z rod falls it will not close the cii flotwipers 262 at d 256 the adjacent contact snri s. The bell crank 273 is pivoted on the horizontal lever shown j to the right of the intersection of its vertical and horizontal arms. The spring shown near the left hand end or" this hell crank is arranged to norn'iallv hold the vertical arm of he bell cranl: 273 in such a position that the hool; on its lower end will be in osition to be engaged bv the. horizontal arin ot the rod HS when the rod M8 returns to normal position. By the energization of magnet 20?. however. the hook on the end of the bell cranl: has been pivoted far enough awa from the horizontal arm of the rod 148 so that the descent of the rod M8 does not operate the springs a 25 and from this combination of operations is omitted for the sake of simplicity and also for the reason that it is unnecessary for an understanding of how connections are made from one station to another.

When the subscriber at the calling s ation hanas up his receiver he opens the circuit of the magnet 112113 of the connector. This permits the armatures of this magnet to fall baclt. The restoration of arm ure 1155 close. the valve 117 and shuts off the supply of air from the motor 118 which falls back. By this operation the holding; cii'ciiitextending back to the magnet. in the selector E is opened. Another result of the motor 118 returning to normal is that it releases pawl 1&0 so that the disk 34-. and associated parts return to normal. Reference is here made to the before cited application tor a detailed description of the connector release. It will sultice to say that the above release of the line relay causes the connector H to be restored to normal.

The release. of the connector also disconnects batterv from the test contact of the called line whereupon the magnet 24. therein deencraiZ-es to restore the circuits of the called line switch to normal.

The dcenergization of the magnet 302 in the selector E releases armature 350. Armature 338 is not released as it is mechanically locked up until the shaft restores to normal. Upon falling back. armature 350 closes valve 3:315 whereby air is disconnected from the sylphon 304.

It will be noted that armature upon falling back opens the springs 368. The holding circuit for the magnet 301 in the selector and the maguetQ in the line switch C is now opened. The svlphon d restores to normal thehv allowing the associated springs to assume their normal position. The inaanet 301 deenergizes as its holdinq circuit is opened therehv allowing the svl phon 307 to deflate. The pawls 318 and ill!) are therebv withdrawn from engagement the latter in'unediatelv reto normal. When the shaft reaches its no, .mal pos tion it actuates the levers 34.0 The ope ation of the lever 340 allows owl.

the nature 3 38 on the coil 302 to retract. The oieratiou or the lever causes the lever 312 to assume its normal position thereby lettings n'ing 313 engage its resting contact. In this manner the selector E is restored to normal.

In the line switch C the relay eraizcd to permit its restoration.

In the above manner the connection is released responsive to the replacement of the receiver at both substations. It is to be noted that this release does not occur until both calling and called subscribers replace their receivers. That is, the last party to hang up causes the release of the connection.

The features of the invention having been described and ascertained, what is considered to be new and desired to have protected by Letters Patent will be pointed out in the appended claims.

' What I claim as my invention is 1. In a telephone system, an automatic switch having a shaft adapted to move in a vertical direction, a pawl for actuating, said shaft, a motor for operating said pawl, said motor normally being in an operated position, a line relay for said switch, and means for energizing said line relay to cause said motor to become deenergized. I

2. In a telephone system, an automatic switch having a shaft, a pawl for actuating said shaft, a motor for operating said pawl, said motor normally being in an operated position, a line relay for said switch, and means for energizing said line relay to cause said motor to become deenergized to operate said shaft.

3. In a telephone system, an automatic switch having a shaft, a pawl for operating said shaft, an air motor for operating said pawl. said motor normally being in an inflated condition, a line relay for said switch, and means for energizing said line relay to cause said motor to deflate to operate said pawl.

4. In a telephone system, an automatic switch having a shaft, means for operating said shaft vertically, means for rotating said shaft, a slow acting device normally energized, a line relay for said switch, and means for energizing said line relay to deenergize said device at the end of the vertical operation of said shaft to initiate the operation of said rotary o crating means.

5. In a teleplione system, an automatic switch having a shaft, a pawl for operating said shaft, an air motor for operating said pawl,said motor normally inflated, a line relay for said switch, means for energizing said line relay to deflate said motor to operate said shaft, and means for maintaining said motor deflated after said shaft is operated.

6. In a telephone system, an automatic switch having wipers, trunk lines accessible to said wipers terminating in contacts arranged in groups, means for operating said wipers vertically step by step opposite a desired one of said groups, an interrupter in said switch consisting of a pneumatic motor and an air valve arranged to control each other to operate the motor for rotating the wipers into engagement successively with the contacts of the desired group, means for automatically initiating the operation of said interrupter after the vertical movement of said wipers, a magnet arranged to have its circuit closed by one a of the wipers when engaging with the contact of an idle trunk line, and means actuated by said magnet forarresting the advance of said wiper.

7. In a telephone system, an automatic switch having wipers, trunk lines accessible to said wipers terminating in contacts arranged in groups, means for operating said wipers vertically step by step opposite a desired one of said groups, an interrupter in said switch consisting of a pneumatic motor and an air valve arranged to control each other to operate the motor for rotating the wipers into engagement successively with the contacts of the desired group, means for automatically initiating the operation of said interrupter after the vertical movement of said wipers, a magnet arranged to have its circuit closed by one of the wipers when engaging with the contact of an idle trunk line, and means actuated by said magnet for arresting the advance of said wiper, and for completing the connection to said idle trunk line.

8. In a telephone, system, an automatic switch having primary and secondary movements, trunk lines terminating in said switch divided into groups, wipers on said switch for engaging with the terminals of said trunk lines, means for operating said switch step by step in its primary movement to select a desired one of said groups, a pneumatic motor for operating said switch step by step in its secondary movement, a source of, air pressure, means for automatically initiating the operation of said motor after said primary movement, means operated by said motor for thereafter intermittently interrupting its own source of air pressure to operate said switch step by step in its secondary movement, a magnet in said switch, means for energizing said magnet when one of the wipers engage with an idle one of said trunk lines, and means operated by said magnet for stopping the operation of said motor and. arresting the movement of said switch.

9. In a telephone system, an automatic switch having primary and secondary movements, trunk lines terminating in said switch and divided into groups, means for operating said switch step by step in its primary movement to select a desired one of said groups, a pneumatic motor for operating said switch in its secondary move ment, a source of air pressure, means for initiating the operation of said motor after said primary movement, and means operated by said motor for thereafter intermittently interrupting its own source of air pressure in its of said third motor, and mean thereafter airy movement to select an idle one operated by said third motor for mtermittently interrupting its own source 0t power erete said switch step by step 1111 said truim lines.

to op soco by said switching relay. '5 Chicago, Illinois, this 21th (luv FRANK A. LUNDQUIST.

first, solely by said line relay and 35 ed d solely 1 June. 19

e y seid secon m. argued ero'iz o ement for de- -o\er moto means 0'' aid peraton tch, a source of power for said third motor, means controlled prlm'try mov change r,

deenergization of s motor to initiate the 0 said by the ter said to:- for said sWi relay eners'lz controller change-owe 

